This invention relates to the production of hydrogen and heat by chemical reaction, and to an apparatus for carrying out the method.
It is generally well known in the chemical field that aluminum reacts with water to spontaneously generate hydrogen and heat. It is also known that the reaction between aluminum and water is not sustainable at ambient temperature due to the protective oxide layer forming on the metal surface. Therefore, the use of aluminum as a fuel to generate heat and hydrogen gas requires that the protective layer be efficiently and continuously removed, and that the reaction be kept at an elevated temperature. A number of hydrogen generators are known to be commercially available for use with fuel cells or as heat sources for thermal engines for examples. These generators are generally complicated and precarious to operate by untrained persons. These hydrogen generators are believed to be designed for use by scientists and other professionals working under laboratory conditions.
Examples of hydrogen production methods and apparatus of the prior art are described in the following documents:
U.S. Pat. No. 3,942,511 issued on Mar. 9, 1976 to Black et al. This document discloses a material for use in diver suits. Magnesium and iron particles are imbedded in the material to react with sea water to produce heat and hydrogen gas for increasing the buoyancy of the diver wearing the suit.
U.S. Pat. No. 3,957,483 issued on May 18, 1976 to M. Suzuki. This patent discloses a magnesium composition for the production of hydrogen. It is taught in this document that the presence of one or more elements selected from the group consisting of sodium chloride (NaCl), potassium chloride (KCl) and various similar metal salts leads to an increase in the quantity of hydrogen gas generated.
U.S. Pat. No. 3,975,913 issued on Aug. 24, 1976 to D. C. Erickson. This document discloses an hydrogen generator using liquid aluminum and water.
U.S. Pat. No. 4,223,661 issued on Sep. 23, 1980 to Sergev et al. This patent discloses the details of a portable heat generating system for divers. The system uses magnesium alloys and seawater which when combined together, produces hydrogen gas and heat energy.
U.S. Pat. No. 4,269,818 issued on May 26,1981 to M. Suzuki. This patent discloses a method for producing hydrogen gas by immersing a piece of magnesium in saltwater.
U.S. Pat. No. 4,340,580 issued on Jul. 20, 1982 to M. Suzuki. This patent is a continuation of the above patent, wherein the method also comprises the application of a direct or an alternating current voltage between a magnesium electrode and another electrode in an electrolyte solution.
U.S. Pat. No. 4,598,552 issued on Jul. 8, 1986 to K. Weber. This patent describes a heat source in which lithium is reacting with water in a reaction chamber to generate heat and hydrogen gas.
U.S. Pat. No. 4,643,166 issued on Feb. 17, 1987 to H. D. Hubele et al. This patent discloses the structure of a fuel cell for producing heat energy and hydrogen gas. The device has a reaction chamber containing a fuel composition that is reactive with water. The fuel composition includes a main fuel part of magnesium and aluminum in a molar ratio of 1:2, and the second part is composed of lithium hydride, magnesium and aluminum in equal molar ratio.
U.S. Pat. No. 4,670,018 issued on Jun. 2, 1987 to J. H. Cornwell. This document describes a log made of compressed wood waste and paper. The log is coated with aluminum particles. Upon burning, the aluminum particles react with moisture in the log to emit great quantity of heat due to the generation of hydrogen gas.
U.S. Pat. No. 4,730,601 issued on Mar. 15, 1988 to N. D. Hubele et al. This patent describes a method for operating a hydrogen and heat producing reaction. The patent is a division of the above patent by the same inventors.
U.S. Pat. No. 4,752,463 issued on Jun. 21, 1988 to K. Nagira et al. This document discloses a material for producing hydrogen gas. The material comprises an aluminum alloy comprising essentially 5 to 50% tin. The disclosure teaches that the hydrogen-producing material reacts with water even at room temperature and produces hydrogen gas with a purity of 99.4% and above.
U.S. Pat. No. 4,769,044 issued on Sep. 6, 1988 to J. H. Cornwell. This patent is a continuation of the patent mentioned above for a log, by the same inventor. In this document, it is taught that the layer of aluminum particles is covered by a layer of paraffin.
U.S. Pat. No. 5,143,047 issued on Sep. 1, 1992 to W. W. Lee. This document discloses an apparatus and a method for generating steam and hydrogen gas. In this apparatus, an aluminum or aluminum alloy powder is reacting with water to generate hydrogen gas. A heat exchanger is provided to extract useful heat. A filter is also provided to remove unwanted reaction byproducts.
U.S. Pat. No. 5,833,934 issued on Nov. 10, 1998 to O. J. Adlhart. This document discloses an hydrogen gas generator using lithium hydride or calcium hydride and water.
U.S. Pat. No. 5,867,978 issued on Feb. 9,1999 to M. Klanchar et al. This document discloses another hydrogen gas generator using a charge of fuel selected from the group consisting of lithium and alloys of lithium and aluminum. The fuel is molten and mixed with water to generate hydrogen gas.
The method for producing hydrogen according to the present invention consists of reacting aluminum with water in the presence of sodium hydroxide as a catalyst. The apparatus according to the present invention uses the pressure and temperature of the reaction to control the degree of immersion of a fuel cartridge in water and consequently to control the vigor and duration of the reaction.
The method and apparatus according to the present invention offer a practical process and a safe device for use by the general public to generate heat, light and hydrogen gas in power outage situations or in remote locations where electricity is not available. Furthermore, the method and apparatus according to the present invention use aluminum waste readily available in domestic garbage and metal working shops, to promote recycling and energy conservation.